#include <iostream>
#include <cstring>
using namespace std;
int main() {
    /*char site[5]={'s','t','y','x','\0'};
    cout<<site<<endl;
    cout<<sizeof(site)<<endl;

    char site1[]="styx";
    cout<<sizeof(site1)<<endl;
    */
    string str1="hello";
    string str2=" world";
    cout<<str1+str2<<endl;

    string str3;
    str3=str1; //复制
    cout<<str3<<endl;

    str3=str1+str2;
    cout<<str3<<endl;
    cout<<str1.size()<<endl;

    return 0;
}
